Refers to when the sun is at its highest and often hottest point in the sky.

Sun Intensity

It specifically denotes 12 PM or the middle of the day, not morning or evening.

Time Specific

Used to describe activities best done when the sun is brightest, like drying clothes.

Activities Context

 "All the labor of all the ages, all the devotion, all the inspiration, all the noonday brightness of human genius are destined to extinction. So now, my friends, if that is true, and it is true, what is the point?" A complicated question.

Maira Kalman: The...

 perception test values when you present those to people who are not well versed in those aspects of science net they become salamanders in the noonday Sun it's like talking about the tangent of the visual angle all right their eyes

Noonday